1. Field of the Invention
This invention relates to methods of treatment of naturally kinky hair, particularly Negroid hair and, more particularly, relates to methods of producing soft, gentle curls in such hair.
2. Brief Description of the Prior Art
The treatment of Negroid hair requires very special attention as a result of the particular characteristics of such hair. Negroid hair is naturally kinky or very tightly curled. There are a variety of approaches to the handling of Negroid hair depending upon the attitude of particular individuals. Some Negroes or blacks prefer to have their hair straightened. Some like to have their hair cut and handled in a way which retains its natural kinkiness or tight curl. Others like to have their hair straightened in a very full manner producing the Afro hairdo. Still others like to have their hair straightened and then curled into soft, gentle curls.
When Negroid hair has been curled in the past, it has been necessary to first straighten the hair by chemical or heat setting techniques and then subjecting the straightened hair to a curling process using rollers and heat or chemical treatment to produce the desired curl. This procedure has required treatments of up to several hours and has required the hair to be maintained on curlers during treatment and drying to produce the desired curl and has also required the use of curlers for resetting between treatments by the barber or the beautician.
There are a large number of U.S. patents which deal with hair waving and hair straightening methods. Patents which have some relevance to the subject invention, are abstracted briefly below. These patents are considered relevant either in the method steps or in providing background or setting for the subject invention or in disclosing chemicals which are used in hair straightening and hair curling methods.
Pileggi, U.S. Pat. No. 2,377,808, discloses a method of curling hair which involves wetting, washing and rinsing hair cut to accept natural curl and followed by a slow dry at 95.degree.-110.degree. F.
Roesch, U.S. Pat. No. 2,865,811, discloses a process of straightening Negroid hair. The hair is shampooed with soap and thioglycolic acid, washed and rinsed, partially dried at 38.degree. C. for 5-10 minutes and then dried with a hot comb at 75.degree.-130.degree. C.
Kalopissis, U.S. Pat. No. 3,063,908, discloses permanent waving using mercaptoamides as a treating reagent.
Kremer, U.S. Pat. No. 3,470,887, discloses a hair straightening process applying a water soluble acidic (pH 1.5-5) cream then a water soluble cream containing a thiol at pH 8.5-9.5.
Wajaroff, U.S. Pat. No. 3,654,936, discloses a hair straightening process by (1) applying a keratine softener, (2) washing out softener, (3) treating with a swelling agent and (4) combing or mechanically straightening.
Kalopissis, U.S. Pat. No. 3,757,804, discloses a hair conditioning and waving process wherein the hair is set on rollers and dried under a hood at 45.degree. C.
Zeffren, U.S. Pat. No. 3,805,809, discloses a curling process using a persulfate treatment shampoo, winding on curlers, and room temperature drying for an extended period of time.
Anderson, U.S. Pat. No. 3,809,098, discloses a curling or straightening process using a persulfate treatment at pH 5-10 and EDTA.
Wajaroff, U.S. Pat. No. 3,880,174, discloses a treatment for curling or straightening hair involving use of an alkaline treating material, mercaptide hardening, and requires the hair to be set on rollers.
Wajaroff, U.S. Pat. No. 3,964,499, discloses a straightening or curling process which uses a fulfite-containing detergent at pH 6-7.5, lauryl alcohol sulfonates as a surfactant, and uses rollers for setting.
Nowak, U.S. Pat. No. 3,972,336, discloses the use of sulfonated polymers in curling or straightening hair.
Minagawa, U.S. Pat. No. 3,973,574, discloses a process for waving and straightening hair by use of an alkaline treatment and a chelating agent.
Edelberg, U.S. Pat. No. 4,038,995, discloses a hair treatment method using a composition containing ammonium or sodium sulfate or bisulfite and a quaternary ammonium salt of a fatty acid and requires the use of curlers.